1. Field of the Invention
A tie strap structure is provided for electric wiring. A tie strap is provided which includes a cross member. The cross member, is slidably received in a mounting bracket having a fastener for securement to an opening. The mounting bracket may be adjusted with respect to the cross member to facilitate alignment of the fastener with the opening.
2. Description of Related Art
The tie strap structure of the present invention is particularly suited to mounting of wiring harnesses in vehicles. Modern vehicles include numerous electrical components. It is necessary to interconnect many of the components with each other for the reason that they frequently have interrelated functions and it is also necessary to connect the electrical components to a source of electrical power This situation has resulted in the need for extensive electrical wiring in vehicles. The electrical wiring is pre-formed into harness structures which are ultimately mounted in vehicles as discrete components. The wiring harnesses are commonly fabricated at a manufacturing facility and subsequently shipped to vehicle assembly plants for mounting in vehicles.
In the manufacture of wiring harnesses, discrete wires are unwound from large spools of wire and cut into desired lengths. The individual wires are then formed into bundles of wires of suitable length and type. Main portions of such bundles are usually secured together and protected from abrasion by use of a sheath which surrounds such bundle portions.
As will be appreciated, wiring harnesses, when assembled in vehicles, must be properly routed and secured in place. One common means for securing wiring harnesses in place is to secure a fastening device to the bundle of wires by means of a flexible tie strap. The tie strap includes a fastener which is quickly and easily secured in place by means of pre-punched openings provided in the vehicle sheet metal. In the manufacture of wiring harnesses, the tie straps are secured to the wiring harnesses at predetermined locations along the length of the harnesses. These locations correspond to openings provided in vehicle sheet metal.
In the initial manufacture of wiring harnesses, the tie straps are properly positioned along the length of the harnesses. However, the discrete wires which form the harnesses are initially wound onto spools and placed in minor tension so that the spool coils will be tightly wound. After the wires are unwound from the spools and formed into wiring harnesses, the tension is relieved. Such tension does result in slight elongation of the wires. Wires, being somewhat elastomeric, will tend to resume their normal length after the tension is relieved. Thus, even though the tie straps are initially properly located, the slight shrinkage in wiring harness length resulting from the removal of tension causes minor dislocation of the tie straps along the wiring harnesses. This shrinkage is a relatively slow process and also is not uniform and therefore cannot be predetermined which would permit compensating for such shrinkage during manufacture of the wiring harnesses. As a consequence, when it is attempted to mount the wiring harnesses in vehicles at an assembly plant, the fasteners of the tie straps frequently are not in exact alignment with the openings in the sheet metal of the vehicles. In order to attach the fasteners, assembly workers have commonly stretched the wiring harnesses a slight bit. Such stretching is undesirable because it requires the assembly worker to take a longer time to mount the harnesses.
In accordance with the present invention, this problem is resolved by providing tie strap structures having slidable mounting brackets which may easily be adjusted short distances to align the tie strap fasteners with the openings in the vehicle sheet metal.